Pleasants Creek - Project Assessment and Design - Winters, CA

Pleasants Creek is a tributary to Putah Creek that has responded negatively to the changes imposed to the flow regime as a result of the Solano Project (Monticello Dam).  The deep incision has created substantial instability in the system that now claims valuable agricultural land each year through lateral erosion.

Due to the impressive depth of incision (20 feet in some areas) the efforts to stabilize the eroding stream banks are challenging.  StreamWise designed and installed several pilot projects to assess the effectiveness of various techniques to slow the rate of land loss and sediment production coming from Pleasants Creek.  Not all efforts have been fully successful.  Flood energy contained within the confines of a deeply incised channel can undo some of the stoutest efforts at stabilization.  However, each project and each passing flow season provide additional insight into techniques that provide the most cost-effective means of addressing landowner and water agency concerns over erosion in the Pleasants Creek watershed.

In 2009, StreamWise will assess a six-mile reach of Pleasants Creek and recommend actions to help slow the chronic lateral erosion of the stream banks.  Recommendations will be based on previous work that has proven effective in these difficult settings.  While full restoration of the channel and floodplain connection is not possible in this developed region, certain methods of stabilization have proven effective.  Efforts to stabilize the toe of eroding slopes with rock vane structures designed to divert flow to the central channel area are promising.

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Rock cross-vane and j-hook vanes installed at Nichols property on Pleasants Creek.  2008 photo